POS0614 THE RELATIONSHIP BETWEEN DISEASE ACTIVITY AND FINANCIAL TOXICITY IN PATIENTS WITH RHEUMATOID ARTHRITIS ON BIOLOGICS: A CROSS-SECTIONAL STUDY USING THE JAPANESE RHEUMATOID ARTHRITIS REGISTRY
Authors: R. Inoue, N. Yajima, T. Matsui, S. Tohma
Journal: Annals of the Rheumatic Diseases (2022)

Background As the number of rheumatoid arthritis (RA) patients using biologics increases, the health financial issues posed by biologics become more important. The health financial issues posed by biologics have been discussed using health economic indicators such as incremental cost-effectiveness ratios (ICERs), but have not been evaluated using the financial burden of medical expenses (financial toxicity). In the field of malignancies, evaluations using financial burden have been conducted and have shown that the stage of malignancy is associated with financial toxicity. It is not known whether disease activity and financial toxicity are similarly associated in RA patients. Objectives This study aims to evaluate the relationship between RA activity and financial toxicity in RA patients using biologics, who are especially likely to feel the financial burdens. Methods We conducted a cross-sectional study of biologic users enrolled in NinJa2020, a database of rheumatoid arthritis patients in Japan collected from April 1, 2020 to March 31, 2021. We defined the users of TNF inhibitor, IL-6 receptor antagonists, T-cell costimulation blocker, Janus kinase inhibitor and biosimilar as biologic users. The main exposure was the disease activity of RA and was measured using DAS28-CRP. Outcome measure was a financial toxicity and was measured using COmprehensive Score for financial Toxicity (COST). This scale is a patient-reported outcome measure (PROM) consisting of 11 items. The responses are recorded on 5-point Likert Scales (ranging from 0 = strongly disagree to 4 = strongly agree). The score by domains ranges from 0 to 44. Higher scores indicated better results and lower financial toxicity. Multiple linear regression models adjusted for age, sex, disease duration, co-payments for anti-rheumatic drugs, work status, financial support systems were conducted to assess the relationship between the disease activity of RA and financial toxicity. As a secondary analysis, we excluded patients with zero copayments and performed the same analysis as in the main analysis. We used multiple imputation to deal with missing values. Results Among 15553 cases in the NinJa database, 649 cases for which RA disease activity and COST were available were included. The median age of the patients was 70 (interquartile range [IQR],56 -77), 83.7% were female. The median copayment amount was ¥12978 per month (IQR 637.2 to 24204.1). The median DAS28-CRP was 1.99 (IQR, 1. - 2.72). The median financial toxicity (COST score) was 21 (IQR 0-27) (Figure 1). In the main analysis using multiple linear regression, COST significantly decreased with disease activity of RA (per 1-pt DAS28-CRP, -1.16 [95% CI -2.04 - -0.28]). In the secondary analysis, COST significantly decreased with disease activity of RA (per 1-pt DAS28-CRP, -1.69 [95% CI -2.29 - -1.10]). Statistical significance was defined as a two-sided p-value &lt; 0.05. All statistical analyses were conducted using STATA 17.0 (Stata Corp LP, College Station, TX). The National Hospital Organization’s research ethics committees evaluated and authorized the NinJa study. Conclusion High disease activity of RA was associated with high financial toxicity in biologic users. We reaffirmed the importance of financial considerations and empathy for RA patients using biologics, and suggested a potential demand for more financial support for RA patients who are refractory to treatment. Disclosure of Interests None declared